Nanorefrigerant effect on performance of domestic refrigerator

www.ijcrt.org © 2018 IJCRT | Volume 6, Issue 2 April 2018 | ISSN: 2320-2882

IJCRT1812587 International Journal of Creative Research Thoughts (IJCRT) www.ijcrt.org 1254

Nanorefrigerant effect on performance of domestic

refrigerator: A Review

1Nihit D. Doshi 1Post Graduate Student

1ME – Thermal Engineering 1SVMIT, Bharuch 392001, INDIA

Abstract: Vapor compression refrigeration systems consume high-grade energy and contribute to global

warming and ozone layer depletion due to the environmentally unfriendly refrigerants. The use of

nanorefrigerants offer good performance in domestic refrigerator in terms of energy consumption and cooling

time. In this study, a review of the previous studies carried out with the use of nanorefrigerants in refrigeration is

presented. An attempt has been made to cover the current status, possibilities, and problems related to the use of

nanorefrigerants as alternative refrigerants. Nanorefrigerant properties, environmental impact and characteristic

are also presented. Results showed that nanorefrigerants can offer proper refrigerants as compare to hydrocarbons

from the standpoint of environment impact, energy efficiency, Energy consumption and compressor discharge

temperatures.

Keywords - Nanorefrigerant, Domestic refrigerator, Power consumption, Cooling time.

I. INTRODUCTION

1.1 DOMESTIC REFRIGERATOR:

A domestic refrigerator has become one of the most important household appliances all over the world. More

than millions of domestic refrigerators are manufactured by many company every year. A domestic refrigerator is

small cold storage where several food products such as ice cream, meat, fish, milk, fruits, vegetables, water etc. can

be stored at reduced temperatures. The most common domestic refrigerator uses a vapour compression refrigeration

system for maintaining required storage conditions, even though many refrigerators use the principle of triple fluid

vapour absorption refrigeration system. Domestic refrigerators are available in many sizes and designs. The domestic

refrigerator is specified by the storage volume (gross or net), like a 300 litre refrigerator means a domestic

refrigerator with an internal storage volume of 300 litres. The domestic refrigerators are available in many sizes from

about 100 litres to about 600 litres. Currently, most of these units use either HFC-134a or hydrocarbons as

refrigerants. They use hermetic compressor with a capillary tube as an expansion device. The condenser of small

refrigerators are of natural convection type, while larger refrigerators may have a fan for forced air circulation over

the condenser.

1.1.1 Internal parts of the Domestic Refrigerator

The internal parts of the refrigerator are ones that do actual working of the refrigerator. Some of the internal parts

are located at the back of the refrigerator and some inside the main compartment of the refrigerator. Some internal

parts of the domestic refrigeratror are:

1)Refrigerant: The refrigerant flows through all the internal parts of the refrigerator. It is the refrigerant by which the

cooling effect occurred in the evaporator. It absorbs the heat from the substance to be cooled in the evaporator and

release it to the atmosphere via condenser.

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2) Compressor: The compressor is located at the back of the refrigerator and in the bottom area. The compressor

sucks the refrigerant from the evaporator and discharges it at high pressure and temperature. The compressor is run by

the electric motor and it is the major power consuming component of the refrigerator.

3) Condenser: The condenser is the thin coil of tube of copper located at the back of the refrigerator. The refrigerant

from the compressor enters the condenser where it is cooled by the atmospheric air thus losing heat absorbed by it in

the evaporator and the compressor. Fins are placed in the condenser for increasing heat transfer rate.

4) Expansion valve or the capillary: The refrigerant leaving the condenser enters the expansion valve. When

the refrigerant is passed through the capillary its pressure and temperature decreases suddenly.

5) Evaporator or Chiller: The refrigerant at very low pressure and temperature enters the evaporator or the

freezer. Generally in domestic refrigerators the plate types of evaporator is used. The refrigerant takes the heat

from the substance to be cooled in the evaporator and evaporated then it is sucked by the compressor. This cycle keeps

on repeating.

6) Thermostat: To control the temperature inside the refrigerator thermostat is used and sensor of it is connected

to the evaporator. The thermostat setting can be done by the round knob inside the refrigerator compartment. When

the set temperature is reached inside the refrigerator the thermostat stops the electric supply to the compressor and

compressor stops and when the temperature decreases below certain level it restarts the supply to the compressor.

7) Defrost System: The defrost system of the refrigerator removes the excess ice from the surface of the evaporator.

The defrost system can be operated manually by the thermostat button or there is automatic system consists of the

electric heater and the timer.

The external parts of the refrigerator are: freezer compartment, thermostat control, refrigerator compartment, crisper,

refrigerator door compartment, light switch etc.

1.1.2 External parts of the Domestic Refrigerator

The external parts of the compressor are the parts that can be seen externally and used for the many purposes.

1) Freezer compartment: The food items that are to be placed at the freezing temperature are stored in the freezer

compartment. The temperature here is below zero degree Celsius so the water and many other fluids freeze in this

compartment.

2) Thermostat control: The thermostat control consists of the round knob with the temperature scale that maintain

the required temperature inside the refrigerator. Proper setting of the thermostat as per the requirements save the lots of

refrigerator electricity bills.

3) Refrigerator compartment: The refrigerator compartment is the biggest part of the refrigerator. All the food

items that are to be maintained at temperature above zero degree Celsius but in cooled condition are placed in this

compartment. The refrigerator compartment can be divided into number of smaller shelves like meat keeper and others

as per the requirement.

4) Crisper: The highest temperature in the refrigerator compartment is maintained in the crisper. The food items

that can remain fresh even at the medium temperature like fruits, vegetables, etc in this part.




5) Refrigerator door compartment: There are number of smaller subsections in the refrigerator main door

compartment. Many of these are egg compartment, butter, dairy, etc.

6) Switch: This is the small button that operates the small light inside the refrigerator. As soon the door of the

refrigerator opens, it supplies electricity to the bulb and it starts, while when it is closed the light from the bulb stops.

This helps in starting the internal bulb only when required.

1.2 HISTORY OF REFRIGERANT:

Refrigerant:

Refrigerants are the working medium used in refrigerating systems which evaporates by absorbing the heat from the

space that is to be cooled and producing the cooling effect.

First Generation Refrigerants

At the starting of 19th century mechanical refrigeration were characterized by use of natural refrigerants.

Refrigerators that were built in the late 1800s to 1929 used the first generation refrigerants like methyl chloride,

ammonia and sulphur dioxide. The common refrigerants for the first hundred years included whatever worked and

whatever was available. Approximately all the first generation refrigerants were flammable, toxic or both and highly

reactive.

Ammonia

It is denoted by R717 and is also a very old refrigerant used in vapour compression and absorption refrigeration

systems. They have a lower molecular weight, wide range of working temperature because of its high critical point,

high latent heat of vapourization and easy leak detection. It is highly toxic, highly irritating and flammable.

Sulphur Dioxide

Sulphur dioxide is generally used in 1920s and 1930s and it has been replaced first by methyl chloride and later by

more favourable fluorocarbon refrigerants. It is highly toxic but non- explosive and non-flammable. It is non-

corrosive in pure state but when it combines with mois- ture it forms sulphurous acids and sulphuric acids which are

highly corrosive.

Methyl Chloride

Methyl chloride was first used in 1878. Methyl chloride is a colourless extremely flammable gas with a mildly sweet

odour. Methyl chloride is corrosive to aluminium, zinc, magnesium.

Second Generation Refrigerants

The second generation refrigerants were found by a shift to chlorofluoro chemicals for safety and durability. They

disregarded compounds that are unstable, toxic, yielding insufficient volatility and inert gases based on their low

boiling point. In 1928, Midgley and his colleagues done critical observations of flammability and toxicity of

compounds containing elements like carbon, nitrogen, oxygen, sulphur, hydrogen, fluorine, chlorine and bromine.

Their first publication was on fluorochloro refrigerants and it showed how the variation of chlorination and

fluorination of hydrocarbons influences boiling point, flammability and toxicity of the refrigerants. Thus CFC

refrigerants used as the second generation of refrigerants. CFC is a non-toxic, non-flammable gas with high mass. It

is a good refrigerant because it can be compressed easily to liquid and rejects lots of heat when it evaporates.

R-11

R 11 is non-flammable and non-explosive. So it can be considered as safe. It is used in the applications like air

conditioning of small buildings, factories, departmental stores, theatres etc.




R-12

R12 is a highly versatile refrigerant that is used for wide range of refrigeration and air conditioning applications. R12

is non-toxic, non-flammable, and non-explosive. It is suitable for wide range of operating conditions.

Third Generation Refrigerants

The third generation refrigerants based on hydro chlorofluorocarbon (HCFC) and hydro fluorocarbon (HFC) have

been developed to replace second generation refrigerants. The advantages of it is same as CFC without damaging the

EarthâĂŹs ozone layer, but they were developed before the environmental impact of fluorine was fully understood.

This effect has been termed as Global Warming Potential (GWP).

Next Generation Refrigerants

HCFC/HFC such as R22 and R134a are on the way to phase-out due to environmental concern. Under medium

and long term refrigerants like HFC chlorine free and their blend, low GWP refrigerant (R1234yf,1234ze) and

halogen free refrigerant (natural refrigerant) are looking as the feasible options for future refrigerant at current

position.

Figure 1.1: Generation of Refrigerant




Table 1.1: Environment properties of Refrigerants

Type ASHRAE

number

Chemical name Chemical formula ODP GWP

CFCs R11 Trichlorofluoro methane CCl2F 1 4750

CFCs R12 Dichlorodifluoro methane CCl2F2 1 10900

HCFCs R22 Chlorodifluoro methane CHClF2 0.05 1810

HCFCs R141b 1,1-Dichloro-

1-1fluoroethane

C2H3FCl2 0.12 725

HFCs R407c R32/125/143a 23±2%CH2F2

25±2%C2HF5

52±2%C2H2F4

0 1774

HFOs R1234yf 2,3,3,3-Tetrafluoro propane C3H2F4 0 4

HC R290 Propane C3H8 0 3.3

HC R600a Isobutane C4H10 0 3

Table 1.2: Thermodynamic properties of the refrigerants

ASHRAE

number

Atmospheric life

(year)

Molecular mass Critical

pressure

(Kg/mol)

Normal boiling

point (bar)

Critical temperature

(℃)

R11 45 137.4 4408 23.77 197.96

R12 100 120.9 4136 -29.8 111.97

R22 12 86.5 4990 -40.7 96.14

R141b 9.3 116.9 4250 32 204.2

R407c 15.657 86.2 4634 -43.8 86.05

R1234yf 0.0301 114 —– -29.4 ——

R290 12 44.1 4248 -42.1 96.7

R600a 12 58.1 3640 -11.7 134.7

1.3 NANO REFRIGERANT:

A nano-refrigerant is a special class of refrigerant in which the nanoparticles are suspended and immersed in the base

refrigerant. The concept of immersing the solid particles into a fluid was first said by Maxwell (1873). He immersed

millimetre and micrometre sized particles into the base fluid in order to increase the thermos physical properties of

the fluid. With the advent of nanotechnology, Choi (1995) gave a new concept of immersing nanoparticles in the




base fluid and called it as nanofluids. The purpose of the development of nanofluids is to increase the heat transfer

performance of various heat transfer fluids and lately, this concept has been extended to the refrigerants as well.

The key points of nano refrigerants are:-

1) The use of nano refrigerants will increase in smaller and lighter refrigeration systems.

2) The refrigeration systems using of nanorefrigerants will consume less compressor power it means they will be

more energy efficient.

There were three main advantages by using nanoparticle in the refrigerator. Firstly, nanoparticles can increase the

solubility between the lubricant and the refrigerant. For example, TiO2 nanoparticles could be used as additives to

increase the solubility between mineral oil and hydrofluorocarbon (HFC) refrigerant. The refrigeration systems

using the mixture of R134a and mineral oil added with nanoparticles TiO2 gives better performance by returning

more lubricant oil back to the compressor and have the similar performance compared to the systems using polyol-ester

(POE) and R134a. Secondly, the thermal conductivity and heat transfer characteristics of the refrigerants should be

increased which have been sanctioned by a lot of investigations. Boiling heat transfer characteristics of Al2O3

nanoparticles mixed in R22 refrigerant increase the heat transfer characteristic of the refrigerant and the bubble size

decrease and move rapidly near the heat transfer surface. Finally, nanoparticles immersed in lubricant should decrease

the friction coefficient and wear rate. The friction coefficient of the mineral oil immersed with 0.1 vol.% fullerene

nanoparticles decrease compare to raw lubricant which increase the efficiency of the compressor.

The nanoparticles can be appended into the refrigeration system in two different ways. In one way the nanoparticles

can be appended to the refrigeration system by first adding them into the lubricant to make a nanoparticles and

lubricant mixture. Then the mixtures put into the compressor as the lubricant. In the other way nanoparticles and

traditional refrigerant can be dispersed directly to make nano-refrigerant. Both ways improve performance of the

refrigerator with the appended nanoparticles. Isobutane (R600a) is more widely used in domestic refrigerator be-

cause of its better energy performances.

In fact, many researchers have studied other thermophysical properties as well such as viscosity, specific heat and

surface tension. The study of boiling heat transfer involves complexities and these complexities increases due to the

addition of nanoparticles in the refrigerant. In past, various results have been done in which the boiling heat transfer

performance for nanorefrigerants was found to be higher in comparison to that of the base refrigerant without

nanoparticles. Major work has been done using refrigerant nanolubricant pair. The friction coefficient decreases upto

90 % when raw oil is replaced by nano-oil and it has better lubricating characteristics in comparison to the raw oil.

Fullerene C60 nano-oil increases the COPs of the compressors and decreases in the compressor shell temperatures

which is desirable since a lower compressor shell temperature improve lubricant stability.

Nanofluids as an advanced type of working fluid have attracted due to their capabilities in heat transfer enhancement.

Nanofluids are mixtures of ultrafine particles and common working fluids such as water and oil. When a refrigerant is

used as the base fluid the suspension is called a nanorefrigerant. By adding the flow boiling of CuO nanoparticles in a

mixture of R134a/polyol-easter oil (POE) with 0.5 % weight concentration has no effect on heat transfer

enhancement. The R134a/Al2O3 nanorefrigerant with a refrigerator save the energy and increase COP. The

concentration of the flow boiling characteristics of the R113/CuO nanorefrigerant inside a horizontal tube at

different nanoparticle concentrations increase the heat transfer.

R134a/SiO2 nanorefrigerant having different volume concentrations decrease in convective boiling heat transfer

coefficient compared to pure R134a. The R134a/POE mixtures having CuO nanoparticles with different volume

fractions increases the heat transfer with increasing volume fractions. Polyolester lubricant of different mass

fraction and volume fraction of Al2O3 nanoparticles increases the heat transfer using Al2O3 nanoparticles instead of

an R134a/polyolester mixture. The usage of nanorefrigerant in the refrigerant system increases COP and minimizes




the length of the capillary tube and it is also cost effective. The potential of R12/TiO2/mineral oil nanorefrigerant

enhances the COP of a vapor compression refrigeration system. The usage of nanorefrigerant in the vapor-

compression refrigeration system decreases compressor work while increases the COP.

1.4 PROPERTIES OF REFRIGERANTS:

To enable use of smaller compressors and other equipment the refrigerant should have smaller vapor density. To

ensure maximum heat absorption during refrigeration, a refrigerant should have high enthalpy of vaporization.

Thermal conductivity of the refrigerant should be high for rapidly heat transfer during condensation and evaporation.

In order to have large range of isothermal energy transfer, the refrigerant should have critical temperature above the

condensing temperature. To have minimum change in entropy during the throttling process, the specific heat should

be minimum. The refrigerant used in air conditioning, food preservation etc. should not be toxic in nature as they will

come into contact with human beings.

1.4.1 Physical properties of nanorefrigerants

The thermo physical properties and flow properties are important to gauge the effectiveness of a nanofluid or a

nanorefrigerant. The thermal conductivity, viscosity, specific heat, latent heat, density and surface tension are some

of the most important thermo physical properties of a fluid. Most of the research in past have been done on the thermal

conductivity of nanofluids. But lately, the studies based on viscosity have also done. It is important to extend this

research to other thermophysical properties since it will give a good idea of the heat transfer performance of

nanorefrigerants.

1.4.1.1 Thermal conductivity of nanorefrigerants

The thermal conductivity is one of the most important thermophysical property of a nanorefrigerant because the

boiling and convective heat transfer coefficients are a function of the thermal conductivity of the fluid. The thermal

conductivity of nanofluids depends on the thermal conductivity values of nanoparticles and base fluid, nanoparticle

volume fraction, nanoparticle size, temperature, base fluid material.

1.4.1.2 Viscosity of nanorefrigerants

The addition of nanoparticles to the refrigerant increase in viscosity of the resultant nanorefrigerant. The increment in

the thermal conductivity and heat transfer of nanorefrigerant is much higher than the increase in viscosity. The

effective viscosity of a nanorefrigerant increases with an increase in particle volume fraction but decreases with an

increase in temperature.

1.4.1.3 Pressure Drop in nanorefrigerants

The pressure drop in nanorefrigerants increases because of the addition of nanoparticles. The increase in pressure

drop is due to the increase in the effective viscosity of the nanorefrigerant. The specific pressure drop increases with

the increase in the particle volume fraction. The pressure drop of the nanorefrigerant increases with increase in particle

mass fraction.

1.4.1.4 Other thermophysical properties of nanorefrigerants

There are many other properties like specific heat, density, latent heat and surface tension. The specific heat capacity

of nanofluids and nanorefrigerants is thermophysical property which is important because of its uses in energy and

exergy performance analysis of the system. The specific heat of nanofluids rely on the type of nanoparticles, volume

concentration of nanoparticles, temperature and the type of base fluid. Therefore, the specific heat of nanofluids can

either increase or decrease by the addition of nanoparticles.

1.5 ENVIRONMENTAL IMPACT

The halogenated refrigerants have a long history of emission from refrigeration, air conditioning and other uses. The

halogenated refrigerants are a family of chemical compounds come from the hydrocarbons (methane and ethane) by




replacement of chlorine and fluorine atoms for hydrogen. The emission of chlorine and fluorine atoms present in

halogenated refrigerants is liable for the most of environmental effects with serious implications for the future

development of the refrigeration based industries.

1.5.1 Ozone Depletion Potential

The first major environmental effect that affect the refrigeration based industries is ODP due to man made chemicals

into the atmosphere. Chlorine based refrigerants are enough to reach the stratosphere where the chlorine atoms act as

a catalyst to diminish the stratospheric ozone layer (which protects the earth surface from direct UV rays). About 90%

of the ozone exists in the stratosphere between 10 and 50 km above the earth surface.

1.5.2 Global Warming Potential

The second major environmental impact is GWP which is because of the absorption of infrared emissions from the

earth causing an increase in global earth surface temperature. While solar radiation at 5800 K and 1360 W/m2

reaches the earth, more than 30% is reflected back into space and most of the remaining radiation passes through the

atmosphere and arrives the surface. This solar radiation heats up the earth radiating energy with a spectral peak in the

infrared wave- length range. This infrared radiation cannot pass through the atmosphere because of absorption by GHG

including the halogenated refrigerants. As a result, the temperature of atmosphere increases, which is called as the

global warming. During the formulation of Kyoto protocol, countries around the world have voluntarily committed

to decrease the GHG emissions. HFC refrigerants have large values of atmospheric lifetime and GWP compared

to chlorine based refrigerants.

1.6 CHARACTERISTICS OF REFRIGERANTS

Refrigerants are substances that change from the liquid to the gaseous state to reduce the temperature of a devices. This

chemical process is used over and over again in refrigerators, air conditioners and other machines to maintain the items

inside cool. Different refrigerants are used depending on the location, the type of machine and the application of items

that are refrigerated.

1.6.1 Boiling Point

A refrigerant should have a boiling point in a particular range that fits the machine in which it is used. A refrigerant

with a lower boiling point tends to have a better ability to cool. Refrigerants with higher boiling points is more efficient and

do work good in a smaller machine. Most refrigerants have a boiling point between - 27.4 and - 49 degrees Fahrenheit,

though many have a boiling point as high as 48.2 degrees Fahrenheit.

1.6.2 Toxicity

A refrigerant is classified as a Class A refrigerant if there is no toxicity identified in concentrations less than 400 parts per

million. If there is toxicity identified in this small amount, the substance is a Class B refrigerant. Class 1 refrigerants

are completely nonflammable, Class 2 types are moderately flammable and Class 3 substances are highly flammable.

A good refrigerant has the proper combination of safety and functionality.

1.6.3 Stability

Refrigerants must be stable substances that do not decompose under the pressures and temperatures of the refrigerator

system. A less stable substance might dissolve the plastics used in the motor and seals of the system. The refrigerant

should also not react chemically with the lubricants and other substances used in the refrigerator. Originally,

chlorofluorocarbons (CFCs) were used as refrigerants until it was decided that they were unstable when they came

into contact with the ozone particles in the upper atmosphere.




1.6.4 Odor

A good refrigerant has no odor when it is in a low concentration so that the devices does not have a chemical smell at all

times. This refrigerant also has a different odor at higher concentrations so that when a device has chemical leaks,

they can be instantly identified.

1.6.5 Pressure

Generally all the new refrigerants operate at a higher pressure than the refrigerants they replace. In many cases the

pressure can be substantially higher, which means that the refrigerant can be used only in equipment designed to use

it.

1.6.6 Material compatibility

The primary safety concern is with wearing of materials, such as motor insulation, which can lead to electrical

shorts, and seals, which can result in leaks.

1.6.7 Flammability

Leakage of a flammable refrigerant could result in explosions. Some new refrigerants are zeotropes which can change

composition under many leakage scenarios.

II. LITERATURE REVIEW

1. In June 2017, Ms. Vidya N. Lakhorkar, Mr. Sulas G. Borkar [1] worked on Performance Evaluation of Domestic

Refrigerator Using Eco-Friendly Refrigerant: A Review. This paper is a review of one of the ecofriendly

refrigerant used in the domestic refrigerator. The performance of the refrigerator was studied using R134a

refrigerant and mixture of propane R290 and isobutene R600a (50/50). Then this increases performance because

of mixture of propane R290 and isobutene R600a (50/50) was compared with performance of refrigerator

working with R134a and percentage of increment was calculated on the basis of COP, refrigerating effect, power

required to run the compressor, etc. It can be concluded that hydrocarbon refrigerant gives good results as

compared to the existing refrigerant R134a. The hydrocarbon refrigerant have low value of GWP (Global

warming potential) as compared to the R134a. So it does not harm the ozone layer and hydrocarbon can be

consider as ecofriendly refrigerant. It reduces energy consumption by 11.1+% compare to R134a. It increases

COP up to 3.25-3.6%. It also reduces Pull down time 11.6 compare to R134a%.

2. In 2017, Tejaswi Saran Pilla, Pranay Kumar Goud Sunkari et al.[2] worked on Experimental evaluation

Mechanical performance of the compressor with mixed refrigerants R-290 and R-600a. Hence, in the present

work, two refrigerants are chosen (R-290 and R-600a) to evaluate the mechanical performance of compressor of

domestic refrigerators. The present work aims at investigation of mechanical performance of compressor with

mixed refrigerants (R-290 and R-600a). The boiling point of the each of the refrigerant is different and hence the

specific volume occupied by each is different. This in turn affects the work input required. Hence, the present work

is aimed at evaluating the compressor performance with mixed refrigerants. The present work concludes that 60%

of R290 and 40% of R600a composition has better performance in all parameters such as mass flow rate, power

consumption, experimental COP, Carnot COP and discharge temperature. Small compressors can be use instead

of usual one to obtain equal performances by using 10% of R290 and 90% of R600a composition. Because it also

has better performance parameters along with 60% of R290 and 40% of R600a composition and also it consumes

low power hence energy will save. It has highest Carnot COP. It means almost equals to ideal cycle for some

extent.

3. In October 2015, Teboho Ramathe, Zhongjie Huan and Aggrey Mwesigye [3] worked on Experimental Study on

the Thermal Performance of R600a, R290 and R600a/R290 Mixtures in a Retrofit R134a Refrigeration System.

In this paper, the experimental thermodynamic performance evaluation of the hydrocarbons R600a, R290 and




their mixtures used in a vapour compression refrigeration system that utilizes R134a as a working fluid was

carried out. Firstly, a theoretical analysis was developed to evaluate the feasibility of the retrofit by employing

the vapour compression refrigeration cycle. The evaporation temperatures were ranging from -25 ℃ to 3 ℃and

the condensation temperatures ranging from 25 ℃ to 65 ℃with superheating and subcooling degrees constant at 5

℃. The thermodynamic and thermophysical properties were obtained using REFPROP soft- ware. Lastly, based

on the results obtained from the theoretical analysis, the experimental comparison of the refrigeration cycle

performance was conducted using a refrigeration system designed for R l34a. The results show that both pure

R600a and R290 cannot be recommended as drop-in substitutes for R134a due to their significant differences in

thermophysical properties. A mixture of R600alR290 50%/50% composition was found to be the most

appropriate alternative refrigerant for the Rl34a system retrofit with a comparative thermal performance.

Hydrocarbons perform favourably in comparison with halo- carbon refrigerants.

4. In June 2015, DEEPAK PALIWAL, S.P.S.RAJPUT [4] worked on EXPERIMENTAL ANALYSIS OF

HYDROCARBON MIXTURES AS THE NEW REFRIGERANT IN DOMESTIC REFRIGERATION

SYSTEM. As and when an existing system of R134a has to be recharged it is suggested to retrofit the system

with new/natural and alternative refrigerants. This investigation focuses on mixture ratio of pure hydrocarbon

R290 and R600a uses in 200 liter domestic refrigeration system by certain changes in condenser and capillary.

The outcome of this work is 80g mixture of R600a/R290 (60/40 by wt%) give better performance than 80g mixture

of R600a/R290 (70/30 by wt%). COP of R600a/R290 (60/40 by wt%) mixture is higher in the range 22%-26.3%

than mixture R600a/R290 (70/30 by wt%) for capillary of 3.5m length and 0.036 inches diameter. During the

experiments it is found that 0.036 inches dia. capillary is more suitable as expansion device than 0.031 inches dia.

capillary at all length . It is also find out that by increasing the length of capillary in the system hydrocarbon

mixture give better results. Refrigerating effect of R600a/R290 (60/40 by wt%) mixture was higher in the range

26.8%-37% in lower evaporating temp. and higher 22.8% -48.8% in higher evaporating temp. than R600a/R290

(70/30 by wt %) for 3.5m length capillary 0.031 inches dia. and 0.036 inches diameter. Energy Consumption of

R600a/R290 (60/40 by wt %) mixture was higher in the range 19.6% - 30.7% than R600a/R290 (70/30 by wt %)

mixture for capillary 3.5 M length and .036 inches diameter.

5. In May 2014, Mao-Gang He, Xin-Zhou Song et al. [5] worked on Application of Natural Refrigerant Propane and

Propane/Isobutane in Large Capacity Chest Freezer. In this paper, some researches have been conducted on

natural refrigerant propane (R290) and its mixtures substituting for 1,1,1,2-Tetrafluoroethane (R134a) used in a

large-capacity chest freezer (BD-625). To examine the application possibilities of R290 and its mixtures to the

large-capacity freezer, their thermodynamic and refrigeration performances from both theoretical analysis and

experimental test have been done. The theoretical analysis shows that R290 is higher by 87.7% and 54.2% than

R134a in mass and volumetric refrigerating capacity respectively. Propane/Isobutene (R290/R600a, 90/10 wt%)

is higher by 48.3% and 2.4% than R134a in volumetric refrigerating capacity and COP respectively. So R290

and its mixtures (R290/R600a) can meet the requirements of large-capacity refrigeration and energy

conservation as the alternatives of R134a. The experimental test shows that the power consumption of the

experimental freezer charged with R290 is lower by 26.7% than that of R134a. The ratio of R290/R600a is

93.75/6.25Wt% when it is used in the freezer and the corresponding power consumption is lower by 27.5% than

that of R134a. The charging amount of R290 is less than that of R134a, which is in line with the safety standards,

So R290 can be used in the large capacity chest freezer. The COP of R290 is lower by about 4.7% than that of

R600a from the theoretical calculation. The experimental test shows the power consumption of the ratio

R290/R600a is 1.71 kWh/24h, which is lower by 1.2% than that of R290 in the tested freezer.

6. In July 2013, Mehdi Rasti, SeyedFoad Aghamiri et al. [6] worked on Energy efficiency enhancement of a domestic

refrigerator using R436A and R600a as alternative refrigerants to R134a. This paper is devoted to feasibility study

of substitution of two hydrocarbon refrigerants instead of R134a in a domestic refrigerator. Experiments are

designed on a refrigerator manufactured for 105 g R134a charge. The effect of parameters including refrigerant




type, refrigerant charge and compressor type are investigated. This research is conducted using R436A (mixture

of 46% iso-butane and 54% propane) and R600a (pure iso-butane) as hydrocarbon refrigerants, HFC type

compressor (designed for R134a) and HC type compressor (designed for R600a). It can be concluded that for HFC

type compressor, the optimum refrigerant charges are 60 g and 55 g for R436A and R600a. Moreover, for this type of

compressor, the energy consumption of R436A and R600a at the optimum charges is reduced about 14% and 7% in

comparison to R134a. On the other hand, when using HC type compressor, the optimum refrigerant charges for

R436A and R600a are both 50 g, and the energy consumption of R436A and R600a at the optimum charges are

reduced about 14.6% and 18.7%, respectively.

7. In September 2008, M. Mohanraj, S. Jayaraj et al. [7] worked on Experimental investigation of R290/R600a

mixture as an alternative to R134a in a domestic refrigerator. In the present work, an experimental investigation

has been made with hydrocarbon refrigerant mixture (composed of R290 and R600a in the ratio of 45.2:54.8 by

weight) as an alternative to R134a in a 200 l single evaporator domestic refrigerator. Continuous running tests

were performed under different ambient temperatures (24, 28, 32, 38 and 43 âŮęC), while cycling running

(ON/OFF) tests were carried out only at 32 C ambient temperature. It can be concluded that the hydrocarbon

mixture has lower values of energy consumption; pull down time and ON time ratio by about 11.1%, 11.6% and

13.2%, respectively, with 3.25 to 3.6% higher coefficient of performance (COP). The discharge temperature of

hydrocarbon mixture was found to be 8.5 to 13.4 K lower than that of R134a. Hence, the life of the compressor can

be improved. Temperature variation in the evaporator is found to be within 3 K. The miscibility of HCM with POE

was found to be good. 8. HCM also reduce the indirect global warming due to its higher energy efficiency. The

overall performance has proved that the above hydrocarbon refrigerant mixture could be the best long term

alternative to phase out R134a.

8. In January 2006, M. Fatouh, M. El Kafafy [8] worked on Assessment of propane or commercial butane mixtures as

possible alternatives to R134a in domestic refrigerators. The possibility of using hydrocarbon mixtures as

working fluids to replace R134a in domestic refrigerators has been evaluated through a simulation analysis in

the present work. The performance characteristics of domestic refrigerators were predicted over a wide range of

evaporation temperatures (-35℃to -10 ℃) and condensation temperatures (40℃to 60℃) for various working

fluids such as R134a, propane, commercial butane and propane/isobutane/n-butane mixtures with various

propane mass fractions. The performance characteristics of the considered domestic refrigerator were

identified by the coefficient of performance (COP), volumetric cooling capacity, cooling capacity, condenser

capacity, input power to compressor, discharge temperature, pressure ratio and refrigerant mass flow rate. It can

be concluded that pure propane could not be used as a drop in replacement for R134a in domestic refrigerators

because of its high operating pressures and low COP. The coefficient of performance of the domestic refrigerator

using a ternary hydrocarbon mixture with propane mass fractions from 0.5 to 0.7 is higher than that of R134a.

Comparison among the considered working fluids confirmed that the average refrigerant mass flow rate of the

propane/commercial butane mixture is 50% lower than that of R134a. The pressure ratio of the hydrocarbon

mixture with 50%, 60% and 70% propane is lower than that of R134a by about 6.3%, 11.1% and 15.3%,

respectively. Finally, the reported results confirmed that the propane/iso-butane/n-butane mixture with 60%

propane is the best drop in replacement for R134a in domestic refrigerators under normal, subtropical and

tropical operating conditions.

9. In March 2004, Somchai Wongwises, Nares Chimres [9] worked on Experimental study of hydrocarbon mixtures

to replace HFC-134a in a domestic refrigerator. This work presents an experimental study on the application of

hydrocarbon mixtures to replace HFC- 134a in a domestic refrigerator. The hydrocarbons investigated are

propane (R290), butane (R600) and isobutane (R600a). A refrigerator designed to work with HFC-134a with a

gross capacity of 239 l is used in the experiment. The consumed energy, compressor power and refrigerant

temperature and pressure at the inlet and outlet of the compressor are recorded and analysed as well as the

distributions of temperature at various positions in the refrigerator. The refrigerant mixtures used are divided into




three groups: the mixture of three hydrocarbons, the mixture of two hydrocarbons and the mixture of two hydro-

carbons and HFC-134a. The experiments are conducted with the refrigerants under the same no load condition

at a surrounding temperature of 25 ℃. It can be concluded that propane/butane 60%/40% is the most

appropriate alternative refrigerant to HFC-134a. The distributions of temperature in the frozen food storage

compartment and in the fresh food storage compartment in the refrigerator, energy consumed, compressor

power, refrigerant temperature and pressure at the inlet and outlet of the compressor were continuously recorded.

The best alternative mixture of HFC-134a in each group was selected and proposed based on the above

information.

10. In November 2001, Y.S. Lee, C.C. Su [10] worked on Experimental studies of isobutane (R600a) as the refrigerant in

domestic refrigeration system. This paper presents an experimental study on the performance of a domestic vapor-

compression refrigeration system with isobutane (R600a) as the refrigerant. The input power of the compressor

varied between 230 and 300 W, while the amount of the charged refrigerant was about 150 g. The expansion

and heat transfer components of the system were capillary tubes and plate heat exchangers, respectively. The

refrigeration temperatures were set at about 4 and -10℃ to simulate the situations of the cold storage and the

freezing applications. Both normal and extreme conditions were investigated in this work. The COPs of the

domestic vapor- compression refrigeration system under study are between 1.2 and 4.5 in the cold storage

application and between 0.8 and 3.5 in the freezing application. For the inlet temperature of the brine of 4 and -

10℃, the COPs are greater than 3.5 and 2.5 respectively if proper sizes of capillary tubes are chosen. The system

with two capillary tubes in parallel per- forms better in the cold storage and air conditioning applications, while that

with a single tube is suitable in the freezing application.

11. In March 2017, T. Vasudevan, N. Prakash et al. [11] worked on Experimental Investigation on Performance of

Refrigerant System using Titanium Dioxide. This project shows an experimental investigation of constant mass

of refrigerant gases R-134a and R-600a (70g) enhanced with varied TiO2 nanoparticles. Nanoparticles are

converted into nanofluids using distilled water as a base fluid. By adding nanofluid with refrigerants it improves

thermophysical properties and heat transfer characteristics of refrigerant and the concentration used for

preparing nanofluids are (2 g/L, 2.5 g/L). Then Performance test are maintained at steady state includes power

consumption, compressor power input, cooling capacity and coefficient of performance. Analysis was based on

temperature and pressure readings obtained from appropriate gauges and power consumption is recorded by

energy meter which are attached to the kid. It has been noticed that the mechanical properties of finding C.O.P

in refrigeration system is achieved using two refrigerants R-134a and R- 600a with nano fluid. The comparison

itself shows that common water has less efficiency (for R- 134a it is 0.4888 and for R-600a it is 0.402) and it

consume more power (for R-134a it is 70 mins and for R-600a it is 91 mins) but while using nanofluid the efficiency

is increased (R-134a it is 0.5546 and for R-600a it is 0.584) and it consume less power R-134a it is 62 mins and for

R-600a it is 59.25 mins).

12. In April 2017, V.K. Dongare, Jyoti Kadam et al. [12] worked on ENHANCEMENT OF VAPOUR

COMPRESSION REFRIGERATION SYSTEM USING NANOFLUIDS. In past five years, nano-refrigerant

has become the input for large number of experimental and vapours compression systems because of shortage

of energy and environmental considerations. The conventional refrigerants have major role in global warming

and depletion of the ozone layer. By adding nanoparticles with refrigerants the coefficient of performance, heat

transfer rate and thermal conductivity will increased. Because of that power consumption rate will be reduced.

This paper compares coefficient of performance of refrigeration system with nanorefrigerants and without

nanorefrigerants such as R134a, Mo49 and blend of R290 and R600a. The COP of refrigeration system with

nanoparticles is more than COP of refrigeration system without nanoparticles. The COP of refrigeration system

with nanoparticles is increased by 4-5%. COP of CuO nanoparticles is more than Cop of Al2O3 nanoparticles

with refrigerants. COP also differs with types of refrigerants R134a, R290 & R600a. The heat transfer rate and

thermal conductivity of system will increased by using nanorefrigerants.




13. In December 2016, M.S.Bandgar, R. N. Kare et al. [13] worked on VCR SYSTEM USING R-600a/ POE

OIL/MINERAL OIL/NANO-SiO2 AS WORKING FLUID: AN EXPER- IMENTAL INVESTIGATION. The

aim of this work is to evaluate the performance of Vapour Compression Refrigeration System using SiO2 nano

particles mixed with Poly- olester (POE) oil / Mineral oil (MO) as Nano lubricant and R-600a as a refrigerant. This

paper investigates which type of lubricant oil works better with SiO2 nanoparticles in the field of refrigeration.

POE Oil / Mineral Oil are mixed with Silica Nano particles by ultrasonic sonication and stirring process to prepare

the Nano lubricants. These Nano lubricants were used in the compressor of refrigeration system instead of

RL68H oil/SUNISO 3GS oil. An investigation was done on the compatibility of POE/Mineral oil mixed with

Silica (SiO2) Nano powder (at a concentration of 0.5%, 1% and 1.5% by mass fraction) as Nano lubricant. The

replacement of Polyol-ester lubricant by the mineral lubricant mixed with SiO2 reduces power consumption. It

gives better results at mass fraction of 0.5% for all combinations of Nano-oils. It was found that the time

required reducing the temperature of water though 10 ℃is less and the power consumption reduces by

12.02% when POE oil is replaced by a mixture of (MO 0.5% Silica). It has been observed that C.O.P. is increased

by 11.66% when POE is replaced by a Nano lubricant (mineral oil 0.5% of SiO2). The freezing capacity is better at

0.5% of SiO2 and it is highest for system using POE oil mixed with 0.5% SiO2 as lubricant. Thus the use of above

Nano lubricants in refrigeration system is favorable.

14. In 2015, Omer A. Alawi, Nor Azwadi Che Sidik et al. [14] worked on Nanorefrigerant effects in heat transfer

performance and energy consumption reduction: A review. The heat transfer performance and energy

consumption of various thermal devices may be augmented by active and passive techniques. One of the passive

techniques is the addition of nanoparticles to the common heat transfer fluids so that the thermal transport

properties of the prepared suspension (called nanofluid) will be enhanced as compared to the base fluid.

Nanorefrigerants are a special type of nanofluids which are mixtures of nanoparticles and refrigerants and have a

broad range of applications in diverse fields for instance refrigeration systems, air conditioning systems, and heat

exchangers. This review is performed in order to clarify the effect of nanorefrigerant properties on heat transfer

and pressure drop compared to pure refrigerant. Moreover, studies related to the thermophysical properties, and

applications of nanorefrigerants to some specific areas such as domestic refrigerators, heat pipes and air

conditioners are also summarized. Energy consumption can be reduced by using nanorefrigerants. It is reported

that the freezing speed and COP in cooling devices are increased by adding nanoparticles to the refrigerants.

The heat transfer rate and pressure drop increase with increasing nanoparticle proportion. The heat transfer rate

increases with a decreasing nanoparticle dimension while the pressure drop decreases with a decreasing

nanoparticle dimension. The lubricant type has the potential to enhance the heat transfer rate.

15. In April 2015, A.Senthilkumar, R.Praveen [15] worked on PERFORMANCE ANALYSIS OF A DOMESTIC

REFRIGERATOR USING CUO âĂŞR600A NANO REFRIGERANT AS WORKING FLUID. The

application of nano refrigerants in refrigeration system is considered to be a potential way to improve the

energy efficiency and to make the use of environment-friendly refrigerants. In this paper it is reported a method

that uses natural gas to enhance the energy efficiency of refrigeration retorting method employing CuO - R600a

as alternate refrigerants. Thus reliability and performance of nano refrigerant in the working fluid have been

investigated experimentally. A new nano refrigerant is employed in the domestic refrigerator. The performances

of the nano refrigerant, such as the cooling capacity, energy efficiency ratio were determined. Combined with

refrigerator using pure R600a as working fluids. 0.1 & 0.5g/L concentrations of CuO - R600a can save 11.83% and

17.88% energy consumption respectively and the freezing velocity of CuO - R600a was more quickly than the

pure R600a system. So the above works have concluded that CuO - R600a can improve the performance of the

domestic refrigerator.

16. In April 2014, S. A. Fadhilah, R. S. Marhamah et al. [16] worked on Copper Oxide Nanoparticles for

Advanced Refrigerant Thermophysical Properties: Mathematical Modeling. Nanorefrigerant which is one kind




of nanofluids has been introduced as a superior properties refrigerant that increased the heat transfer rate in the

refrigeration system. Many types of materials could be used as the nanoparticles to be suspended into the

conventional refrigerants. In this study, the effect of the suspended copper oxide (CuO) nanoparticles into the

1,1,1,2-tetrafluoroethane, R-134a is investigated by using mathematical modeling. The investigation includes

the thermal conductivity, dynamic viscosity, and heat transfer rate of the nanorefrigerant in a tube of evaporator.

The thermal conductivity of refrigerant-134a is 0.0139 W /mK at temperature of 26℃. Additional 1% volume

fraction has increased the thermal conductivity in range of 3.53âĂŞ8.38% up to 5% volume fraction. The

viscosity of nanorefrigerant is also showing great percentage of enhancement which is about 44.45% once

compared to the conventional refrigerant with only 1% of nanoparticles volume fraction. The heat transfer rate

of a tube of nanorefrigerant with 5% vol. fraction is about 1% enhancement.

17. In April 2013, R. Reji Kumar ,K. Sridhar et al.[17] worked on Heat transfer enhancement in domestic

refrigerator using R600a/mineral oil/nano-Al2O3 as working fluid. Aluminium oxide nanofluid is used for

enhancing the heat transfer capacity of the refrigerant in the refrigeration System. In this experiment heat transfer

enhancement was investigated numerically on the surface of a refrigerator by using Al2O3 nano-refrigerants,

where nanofluids could be a significant factor in maintaining the surface temperature within a required range.

The addition of nanoparticles to the refrigerant results in improvements in the thermophysical properties and heat

transfer characteristics of the refrigerant, thereby improving the performance of the refrigeration system. Stable

nanolubricant has been prepared for the study. The R600a refrigerant and mineral oil mixture with nanoparticles

worked normally. Freezing capacity of the refrigeration system is higher with mineral oil + alumina

nanoparticles oil mixture compared the system with POE oil. The power consumption of the compressor reduces

by 11.5% when the nanolubricant is used instead of conventional POE oil. The coefficient of performance of

the refrigeration system also increases by 19.6 % when the conventional POE oil is replaced with nanorefrigerant.

18. In August 2011, Shengshan Bi, Kai Guo et al. [18] worked on Energy Conversion and Management. In this work,

an experimental work was investigated on the nano-refrigerant. TiO2-R600a nano-refrigerants were used in a

domestic refrigerator without any system re- construction. The refrigerator performance was then investigated

using energy consumption test and freeze capacity test. It can be concluded that TiO2-R600a nano-refrigerants

work normally and safely in the refrigerator. Compared with refrigerator using pure R600a as working fluids, 0.1

and 0.5 g/L concentrations of TiO2-R600a can save 5.94% and 9.60% energy consumption respectively and the

freezing velocity of nanorefrigerant system was more quickly than the pure R600a system. above works have

demonstrated that nanoparticles can improve the performance of the domestic refrigerator.

III CONCLUSION

The present study gives a comprehensive review of the various studies related to use of nanorefrigerants in

refrigeration systems. Based on the results of different studies relevant to nanorefrigerants the following points

can be drawn:

The use of nanorefrigerants as refrigerants are not just good for the environment but also it can reduce the

energy consumption and offer proper refrigerants for the performance of domestic refrigerator.

The convenient thermodynamic and thermo-physical properties of nanorefrigerants assure that the

performance of the domestic refrigerator is comparable to the traditional refrigerants.

Nanorefrigerants offer interesting refrigerant as alternatives for conventional ones from the standpoint of

energy efficiency, cooling time and compressor's discharge-temperatures.




IV ACKNOWLEDGEMENTS

I would like to thank Ass. Professor Hussain Pipwala for his invaluable guidance and patience during this work. He

took great efforts in providing good guidance and was enthusiastic about my work. He gave so many advices on this

work, expressing the idea. It was a pleasure working with him and more importantly, learning from him. I owe him

a great debt of gratitude. Many sincere thanks to Head of Department Dr. S.J.Thanki and Principal Dr. R.G.Kapadia

for the support in this work. I express my deep and sincere sense of gratitude to all the faculty members and institute

staff of Mechanical Engineering at Shri S’ad Vidya Mandal Institute of Technology.

REFERENCES

[1] M. V. N. Lakhorkar and M. S. G. Borkar, “Performance evaluation of domestic refrigerator using eco-friendly refrigerant: A review,”

2017.

[2] T. S. Pilla, P. K. G. Sunkari, S. L. Padmanabhuni, S. S. Nair, and R. S. Dondapati, “Ex- perimental evaluation mechanical performance

of the compressor with mixed refrigerants r-290 and r-600a,” Energy Procedia, vol. 109, pp. 113–121, 2017.

[3] T. Ramathe, Z. Huan, and A. Mwesigye, “Experimental study on the thermal performance of r600a, r290 and r600a/r290 mixtures in a

retrofit r134a refrigeration system,” in In- dustrial and Commercial Use of Energy (ICUE), 2015 International

Conference on the, pp. 178–186, IEEE, 2015.

[4] D. Paliwal and S. Rajput, “Experimental analysis of hydrocarbon mixtures as the new refrigerant in domestic refrigeration system,”

International Journal of Scientific & Engi- neering Research (IOSR-JMCE), vol. 6, no. 6, 2015.

[5] M.-G. He, X.-Z. Song, H. Liu, and Y. Zhang, “Application of natural refrigerant propane and propane/isobutane in large capacity

chest freezer,” Applied Thermal Engineering, vol. 70, no. 1, pp. 732–736, 2014.

[6] M. Rasti, S. Aghamiri, and M.-S. Hatamipour, “Energy efficiency enhancement of a domestic refrigerator using r436a and r600a as

alternative refrigerants to r134a,” Interna- tional Journal of Thermal Sciences, vol. 74, pp. 86–94, 2013.

[7] M. Mohanraj, S. Jayaraj, C. Muraleedharan, and P. Chandrasekar, “Experimental investigation of r290/r600a mixture as an alternative to

r134a in a domestic refrigerator,” Inter- national Journal of Thermal Sciences, vol. 48, no. 5, pp. 1036–1042, 2009.

[8] M. Fatouh and M. El Kafafy, “Assessment of propane/commercial butane mixtures as possible alternatives to r134a in domestic

refrigerators,” Energy Conversion and Management, vol. 47, no. 15, pp. 2644–2658, 2006.

[9] S. Wongwises and N. Chimres, “Experimental study of hydrocarbon mixtures to replace hfc-134a in a domestic refrigerator,” Energy

conversion and management, vol. 46, no. 1, pp. 85–100, 2005.

[10] Y. Lee and C. Su, “Experimental studies of isobutane (r600a) as the refrigerant in domestic refrigeration system,” Applied Thermal

Engineering, vol. 22, no. 5, pp. 507–519, 2002.

[11] T. V. N. P. U. Vishnuprasath and S. P. A. P. C. Chelladurai, “Experimental investigation on performance of refrigerant system using

titanium dioxide,” 2017.

[12] V. Dongare, J. Kadam, A. Samel, R. Pawar, and S. Sarvankar, “Enhancement of vapour compression refrigeration system using

nanofluids,” 2017.

[13] M. Bandgar and R. Kare, “Vcr system using r-600a/poe oil/mineral oil/nano-sio2 as working fluid: An experimental investigation,”

[14] O. A. Alawi, N. A. C. Sidik, and A. S. Kherbeet, “Nanorefrigerant effects in heat transfer performance and energy consumption

reduction: A review,” International Communica- tions in Heat and Mass Transfer, vol. 69, pp. 76–83, 2015.

[15] A. Senthilkumara and R. Praveenb, “Performance analysis of a domestic refrigerator using cuo–r600a nano–refrigerant as working

fluid,” Journal of Chemical and Pharmaceutical Sciences ISSN, vol. 974, p. 2115, 2015.

[16] S. Fadhilah, R. Marhamah, and A. Izzat, “Copper oxide nanoparticles for advanced refrigerant thermophysical properties:

mathematical modeling,” Journal of Nanoparticles, vol. 2014, 2014.

[17] R. R. Kumar, K. Sridhar, and M. Narasimha, “Heat transfer enhancement in domestic refrigerator using r600a/mineral oil/nano-

al2o3 as working fluid,” International Journal of Computational Engineering Research, vol. 3, no. 4, pp. 42–50, 2013.

[18] S. Bi, K. Guo, Z. Liu, and J. Wu, “Performance of a domestic refrigerator using tio 2-r600a nano-refrigerant as working fluid,” Energy

Conversion and Management, vol. 52, no. 1, pp. 733–737, 2011.


Nanorefrigerant effect on performance of domestic refrigerator

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